. . . "C.a.R.\u2013 Compass and Ruler (also known as Z.u.L., which stands for the German \"Zirkel und Lineal\") \u2014 is a free and open source interactive geometry software that can do geometrical constructions in Euclidean and non-Euclidean geometry. The software is Java based. The author is Rene Grothmann of the Catholic University of Eichst\u00E4tt-Ingolstadt.It is licensed under the terms of the GNU General Public License (GPL)."@en . . . . . . . "C.a.R."@en .